Pump throwout device



Ndv. 7, 1950 o. R. SCHOENROCK PUMP THROWOUT DEVICE Filed Aug. 13, 1945 Patented Nov. 7, 1950 PUMP THROWOUT DEVICE Otto R. Schoenrock, Oak Park, Ill., asslgnor to J. I. Case Company, Racine, Wis., a corporation of Wisconsin Application August 13, 1945, Serial No. 610,515

6 Claims. 1

This invention relates to a reciprocating pump. and more particularly to a device associated therewith for disengaging the fluid displacing elements from the driving mechanism.

In connection with certain kinds of machinery, for example, farm machinery, such as tractorpropelled cultivators or combines, it is desirable to provide power-driven means for performing certain operations, e. g., lifting the cultivator shovels out of operative position into transport position or lifting the cutting apparatus of a combine from operative position to a position of nonuse. Hydraulic piston actuators have been provided for this purpose, the pressure liquid to which is supplied by means of piston pumps which are usually driven from some rotatable power-driven part of the machinery. There may be many periods of time in which the machinery will be used for purposes which do not require the use of the hydraulic power piston. If the pump which supplies liquid to the piston is allowed to run, provisions are made whereby this liquid is Toy-passed or recirculated after the power piston has moved to its extreme limit. However, if the pump is allowed to continue to run during periods when there is no need for hydraulic control, there results undue and unnecessary wear on the pump and the transmission from the driving source to the pump.

One or the objects of my invention is to provide manual selectively operable means for disengaging the drive member from the pump, thus doing away with the unnecessary. wear and tear on the pump and associated parts.

Another object is to provide means as aforesaid which, in the case of a pump having a plurality of drive members driving a plurality of pumping pistons, is capable of disengaging all of said pistons simultaneously.

Still a further object is to provide a device as aforesaid which may be adapted to pumps already existing with little or no alteration in the parts.

Further objects and advantages of the invention will be apparent from the description and claims.

My invention will be described as embodied in a reciprocating hydraulic pump as used in connection with a farm tractor adapted to accommodate a variety of farm implements operable in certain respects by a hydraulic cylinder and piston receiving fluid under pressure from the pump. However, it will be comprehended that the invention is capable of being incorporated in pumps for other uses.

One embodiment will be described and shown in the accompanying drawings in which latter:

Fig. 1 is a fragmentary perspective view of the device of the invention; I

Fig. 2 is a fragmentary side elevational view of the device;

Fig. 3 is a cross-sectional view taken on the line 3-3 of Fig. 2; and 1 Fig. 4 is a cross-sectional view of the hydraulic cylinder and piston. Referring to Fig. 1, there is shown a pump 9 associated with a tractor, for example, and comprising a body l0 cross-sectioned to reveal parts within, the body having a pair of cylinders I I in which are adapted to reciprocate the pistons [2. Each piston is provided with an integral enlarged portion or head l3, and a coiled compression spring l4 individual to each piston and intermediate the head l3 and body in serves to urge the pistons normally outwardly of the body. By means of suitable valve means and conduits (not shown), the interior of each cylinder ii is connected to a flexible tube entering the-hydraulic cylinder 16. Since the nature of the means for delivering the fluid under pressure from the pump 9 tothe cylinder 56 is not a limiting feature of my invention, further particulars thereof are deemed unnecessary.

The cylinder i6 is adapted to receive a piston 2i and connecting rod 22, a suitable stufllng box and gland indicated somewhat diagrammatically in the figure serving to seal the cylinder in the usual manner, and the usual vent 20 is provided therefor. The connecting rod 22 is connected to a lever 23 forming a part of the mechanism operated by the cylinder l6 and piston 2!. It will be understood, as mentioned hereinbefore, that the lever 23 may operate a cultivator, a combine, or any other implement to which the tractor may apply a driving force.

Pivotally mounted on a shaft 24 carried in the' pump housing 25 is a pair of bell crank levers or followers 26, each comprising an arm 2! terminating in a rounded head 28 adapted to bear against the outer face of an associated piston head IS. The other arm 3| of each follower 28 carries at its extremity a roller 32 adapted to bear the cams 33 on an angle of 180 with respect to each other, the pistons [2 are reciprocated alternately as is understood in the art.

It will now be apparent that as long as the shaft 34, which is continuously driven by the engine of the tractor, is rotating, the levers 25 will be oscillated about their shaft 24 to actuate the pump pistons l2 and to force fluid through the pump valve means and the controlling valve operating the flow of fluid to the cylinder "5. However, during a major portion of the operating time of the tractor, the pump 9 is not utilized, and it is desired to eliminate wear on the pump and its associated parts. Accordingly, I provide a boss 4| integral with the framework 25 through which is a threaded aperture 42 receiving a screw 43. The screw 43 is positioned so that its axis lies in the plane of juxtaposition 44 of the two levers 26 (Fig. 3) and is thereby adapted, upon being screwed inwardly of the aperture 42, to contact the two levers 2B and force the rollers 32 thereof against the urging of the springs 14 and away from the cams 33. This is clearly shown in Fig. 2 wherein the dot and dash lines represent the two levers 26 after having been moved out of contact with the cams 33. Thus the cams 33 may rotate without oscillating these levers. If desired, a lock nut 45 may be provided on the screw 43 to maintain it in its innermost or outermost positions against accidental movement by vibration. It will be understood that the screw 43 may be replaced by a wing screw having a head designed for easy engagement by the fingers.

When it is desired to restore the pump to service, the screw 43 is rotated in the opposite direction to its normal position as shown in full lines in Fig. 2, and the rollers 32 are permitted to take up their normal operating position in contact with the cams 33.

While I have shown particular embodiments of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made, and I therefore contemplate by the appended claims to cover any such modifications a fall within the true spirit and scope of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A power pump construction comprising a plurality of pistons in parallel side by sideformation having a common discharge passage, each piston having an operating head, a plurality of coaxially mounted two-armed rock levers, one for each piston, each having a rock arm for actuating an operating head, a cam shaft rotatable about an axis parallel to the axis of said rock levers having a plurality of eccentric cams for actuating the other arms of said rock levers, respectively, mounted on said cam shaft, said eccentric cams being angularly displaced about the axis of said shaft to provide a difference in phase of the pistons, and common manually operable abutment means engageable with one arm of each lever and movable from a position in which it does not hold the lever arms out of engagement with the eccentric cams to a position in which it does hold the lever arms out of engagement with the eccentric cams.

2. A power pump construction comprising a plurality of pistons in parallel side by side formation having a common discharge passage, each piston having an operating head, a plurality of coaxially mounted two-armed rock levers, one for each piston, each having a rock arm for actuating an operating head, a cam shaft rotatable about an axis parallel to the axis of said rock levers having a plurality of eccentric cams for actuating the other arms of said rock levers, respectively, mounted on said cam shaft, said eccentric cams being angularly displaced about the axis of said shaft to provide a difference in phase of the pistons, and common manually operable abutment means engageable with one arm of each lever and movable from a position in which it does not hold the lever arms out of engagement with theeccentric cams to a position in which it does hold the lever arms out of engagement with the eccentric cams comprising a screw engageable and disengageable with respect to one arm of each lever.

3. A'po'wer pump construction comprising a piston having an operating head, a two-armed rock lever for said piston having a rock arm for actuating the operating head, a cam shaft having an eccentric cam for actuating the other arm of said rock lever mounted on said cam shaft, and a manually operable abutment engageable with an arm of said lever and movable from a position in which it does not hold the lever arm out of engagement with the eccentric cam to a position in which it does hold the lever arm out of engagement with the eccentric cam comprising a screw mounted for threading axial movement in a plane perpendicular to the axis of said cam shaft.

4. A power-pump construction comprising a piston having an operating head, a, two-armed rock lever for said piston having a rock arm for actuating the operating head, a cam shaft having an eccentric cam for actuating the other arm of said rock lever mounted on said cam shaft, and a manually operable abutment engageable with an arm of said lever and movable from a position in which it does not hold the lever arm out of engagement with the eccentric cam to a position in which it does hold the lever arm out of engagement with the eccentric cam comprising a screw engageabie and disengageable with respect to an arm of the rock lever mounted for threading axial movement in a plane perpendicular to the axis of said cam shaft.

5. -A power pump construction comprising a plurality of pistons in parallel side by side formation having a common discharge passage, each piston having an operating head reciprocable therewith, a plurality of coaxially mounted rock levers, one for each piston, engageable with said heads, respectively, for operating the pistons, a cam shaft rotatable about an axis parallel to the axis of said levers having a plurality of eccentric cams for actuating the levers, respectively, mounted on said cam shaft, said eccentric cams being angularly displaced about the axis of said shaft to provide a difference in phase of the pistons, and common manually operable abutment means engageable with said levers and movable from a position in which it does not hold the levers out of engagement with the eccentric cams to a position in which it does hold the levers out of engagement with the eccentric cams.

6. A power pump construction comprising a piston having an operating head receiprocabie therewith, a rock lever engageable with said head for operating the piston, a cam shaft having an eccentric cam for engaging said lever to actuate it, and a manually operable abutment engageable with said lever and movable from a position in which it does not hold the lever out of engagement with the eccentric cam to a position in which it does hold the lever out of engagement with the eccentric cam comprising a. screw mounted for threading axial movement in a plane perpendicular to the axis or said cam shaft.

OTTO R. SCHOENROCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Number Name Date Clagett Mar. 24, 1925 Welch Oct. 10, 1933 Hejduk Aug. 30, 1938 FOREIGN PATENTS Country Date Germany 1889 

